Scientists discovering more about genetic cues and a person's physical traits

Posted March 27, 2009 - 12:42
by
Rick C. Hodgin

Chicago (IL) - Researchers are beginning to identify the genes which makeup a person's physical traits, including facial structure, skin tone, hair and eye color and more. The technology could be employed in the future in a Gattaca-like way, allowing a genetic approximation of your true appearance merely from a DNA sample.

An article appearing on the Wall Street Journal today suggests this technology could be used by police to create a physical description of a criminal when only a DNA trace is left behind. However, I believe this story has far broader implications.

In the movie Gattaca, DNA was used to classify individuals into their capabilities and limitations before birth. It was already known, based on their DNA profile alone, how much potential a given individual had. A weak heart, for example, might limit their abilities to be strong laborers. A shorter individual might not do so well in sports, etc. All of these cues were taken by genetic markers -- and in the movie the entire society had been adapted into this way of thinking. They even had a term for people who stepped outside of their genetic profile illegally -- they were called broken ladders.

The technology is still very primitive compared to that movie. In 2004, police used a crime-scene DNA sample to correctly identify a black man who had been described by eye-witnesses as white. In England, forensic services has a similar "ethnic inference" test for murders and rapists.

A forensic geneticist named Christopher Phillips at the University of Santiago de Compostelo in Spain, was able to take 34 genetic biomarkers identified in 2007 in a DNA test following the Madrid bombings. In what has possibly been the largest high-profile example to date, a bombing suspect's body was badly damaged by the explosion. By using only the genetic profile, Phillips was able to determine he was of North African origin. Later, using other clues, police were able to determine he was Algerian, thereby validating the analysis.

A University of Texas geneticist named Murray Brilliant is developing a predictive test for skin, eye and hair color. Based on voluntary DNA data given up by 1,000 university students, the research identified five genes that account for 76% of the variations present in hair color, 75% for eye color and 46% for skin color.

A similar Erasmus University study found that a DNA analysis of 6,000 people from the Netherlands resulted in six DNA markers which predicted brown eye color with 93% accuracy, and blue eye color with 91% accuracy.

A similar test for age has been developed by Dr. Ballantyne of the University of Central Florida. It can determine if DNA comes from a newborn or a child that's a few months old. The test uses cues of particularly active sequences during early development. However, the test is not yet accurate enough to determine if a DNA sample comes from a teenager, a 40-year old or someone who's 80 years old. That problem is nowhere near being solved.

Additional tests are being worked up for height, facial features (nose length, width, lips, eyes, brow ridge, cheeks, chin, etc.), and every other trait imaginable.

The culmination of this work is still many, many years away from being assembled into a Gattaca-like test, however all indications are that it is coming. And such a reality raises a question: Are we the sum of our genes? Or is there a driving force behind us allowing one to exceed what might seem like statistical limitations? To answer this question consider the human will. One physically healthy person finds solace in alcohol and does not do much with their life. Another less physically capable person strives and strives and achieves great things.

Are we the sum of our genetic code? Or is there something more?

My fear is that when science identifies the genes which mark an individual's traits to a sufficient degree, the answer to that question will no longer matter as scientists and politicians will be unable to stop themselves from categorizing people based on their genetic markers alone -- rather than accomplishments or worldly influences or circumstances which might encourage them in alternate directions.